Surgical atrial fibrillation treatment involves eliminating the electrical propagation wavelets that trigger and sustain atrial fibrillation, and mitigating the risk of stroke by reducing the volume of enlarged the atria through isolation or resection of the atrial appendages. A previous surgical technique for resecting an atrial appendage involves manually advancing a suture, via an attached, curved, fixed needle, through the atrial appendage. This approach is performed under direct visualization during open heart surgery involving a media sternotomy or lateral thoracostomy. To advance the suture through tissue, the surgeon clamps the solid suture needle with a needle driver clamp and rotates the needle via twisting of the needle driver until the needle and attached suture are advanced through the soft tissue. Once the needle punctures through the soft tissue, the surgeon uses a forcep or the needle driver to grab the distal end of the needle and pull the suture through the puncture site. Once tightened, the suture or sutures employed bear down on the opposing tissue walls of the atrial apendage, thereby closing it off or isolating its interior from the remaining blood pool of the heart.
This technique is adequate when the patient is on cardiopulmonary bypass support and access to the heart is not restricted by the opening into the thoracic cavity, characteristic of a median sternotomy and long lateral thoracotomies. However, during beating heart procedures and minimally invasive access to the heart commonly associated with mini-sternotomies, mini-thoracotomies, port access, and subxiphoid access, such manual surgical techniques require too much time, are accompanied with significant bleeding, and are not able to adequately create the desired suture stitch to completely close the orifice into the atrial appendage.
Less invasive approaches, surgical and catheter-based have been identified to isolate the atrial appendage by a variety of techniques and methodologies. One such approach, as described in U.S. Pat. No. 5,306,234 entitled “Method for closing an atrial appendage”, involves delivering multiple staples through an endoscopic stapler that clamps the atrial appendage and delivers staples between opposite tissue layers to compress the layers together. The stapling approach, however successful, causes abrasion and trauma between the metallic staple and the soft tissue surface. In addition, spacing of the staples determines whether the appendage is completely isolated.
Catheter-based approaches, such as those described in U.S. Pat. No. 6,730,108 entitled “Barrier device for ostium of left atrial appendage”, U.S. Pat. No. 6,689,150 entitled “Filter apparatus for ostium of left atrial appendage”, U.S. Pat. No. 6,652,555 entitled “Barrier device for covering the ostium of left atrial appendage”, U.S. Pat. No. 6,152,144 entitled “Method and device for left atrial appendage occlusion”, U.S. Pat. No. 6,231,561 entitled “Method and apparatus for closing a body lumen”, and U.S. Pat. No. 6,419,669 entitled “Method and apparatus for patching a tissue opening”, describe patches that are positioned at the opening into the atrial appendage to prevent blood and/or clots residing in the atrial appendage from escaping into the blood pool. These approaches leave foreign material exposed to blood flow which material increases the risk of thromboembolism and increases the possibility that patients undergoing this procedure still require anticoagulation regimen such as Coumadin to prevent clots from forming in the heart. In addition, the risk of dislodgement for such patches is high, whether associated with fracture of the patch attachment means, degradation of the patch materials, mechanical damage to the device during manual compression of the heart (e.g. CPR) or other unexpected mechanical manipulation. Any dislodgement of such patch-type devices is life-threatening.
Other approaches such as taught by U.S. Pat. No. 5,865,791 entitled, “Atrial appendage stasis reduction procedure and devices”, U.S. Pat. No. 6,132,438 entitled, “Devices for installing stasis reducing means in body tissue”, describe devices and techniques that place a tie around the atrial appendage and close the opening by tightening the tie into a small diameter loop, or by inserting anchors into tissue separated around the circumference of the opening such that once tightened, the diameter of the opening is decreased until the appendage is isolated from blood flow. These approaches either do not adequately attach the isolation device to the tissue surface or are associated with high stresses at the attachment point, which can lead to tissue abrasion, tearing, or other unwanted tissue response. The latter observation is also true in regard to the simple emplacement of sutures through the opposing atrial appendage walls to close-off the structure, where at the place where the sutures turn they can cut into the tissue.
U.S. patent application Publication No. 2003/0078465 addresses this problem with regard to mattress sutures employed for supporting or reshaping the heart muscle for treatment of congestive heart failure. However, this invention does not teach modes of treatment that are applicable specifically to atrial appendage isolation in terms of placing a pledgeted mattress suture stitch(es) to compress opposing tissue or to prevent its expansion.
As such there exists a need for the present invention in connection with addressing the various deficiencies of known atrial appendage isolation modes as well as extending the applicability of mattress suture applications as applicable to supporting, closing or reshaping tissue cavity regions such as in reduction or isolation of orifices or anatomic cavities such as lung reductions or resections, gastric reductions, and other soft tissue manipulation procedures. As such, the present invention offers a significant advance in the art.